U.S. patent application number 10/023395 was filed with the patent office on 2002-08-15 for system and method for grouping refelectance data.
Invention is credited to Curtiss, Brian, Faus, Robert J., Feldman, Leonid G., Goetz, Alexander.
Application Number | 20020108892 10/023395 |
Document ID | / |
Family ID | 26697080 |
Filed Date | 2002-08-15 |
United States Patent
Application |
20020108892 |
Kind Code |
A1 |
Goetz, Alexander ; et
al. |
August 15, 2002 |
System and method for grouping refelectance data
Abstract
A method of identifying non-conforming groups of items within a
package, the package containing a plurality of groups of items,
comprises obtaining a reference signal corresponding to a package
containing conforming groups of items, obtaining a signal
corresponding to each of the plurality of groups of items in the
package, comparing the signal corresponding to each of the
plurality of groups of items with the reference signal, determining
whether any of the plurality of groups of items is nonconforming,
and segregating the package based on whether the package contains a
nonconforming group of items.
Inventors: |
Goetz, Alexander; (Boulder,
CO) ; Curtiss, Brian; (Boulder, CO) ; Faus,
Robert J.; (Longmont, CO) ; Feldman, Leonid G.;
(Broomfield, CO) |
Correspondence
Address: |
COOLEY GODWARD LLP
ATTN: PATENT GROUP
11951 FREEDOM DRIVE, SUITE 1700
ONE FREEDOM SQUARE- RESTON TOWN CENTER
RESTON
VA
20190-5061
US
|
Family ID: |
26697080 |
Appl. No.: |
10/023395 |
Filed: |
December 20, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60268483 |
Feb 12, 2001 |
|
|
|
Current U.S.
Class: |
209/576 ;
209/587; 209/938; 250/222.2 |
Current CPC
Class: |
G01N 21/274 20130101;
G01N 21/9508 20130101; B07C 5/342 20130101; G01J 2003/2866
20130101 |
Class at
Publication: |
209/576 ;
209/587; 209/938; 250/222.2 |
International
Class: |
B07C 005/00 |
Claims
What is claimed is:
1. A method of identifying non-conforming groups of items within a
package, the package containing a plurality of groups of items, the
method comprising: obtaining a reference signal corresponding to a
package containing conforming groups of items; obtaining a signal
corresponding to each of the plurality of groups of items in the
package; comparing the signal corresponding to each of the
plurality of groups of items with the reference signal; determining
whether any of the plurality of groups of items is nonconforming;
and segregating the package based on whether the package contains a
nonconforming group of items.
2. The method of claim 1, wherein the reference signal is a known
value input by a user.
3. The method of claim 1, wherein the reference signal is obtained
by performing a calibration run on a package containing conforming
groups of items.
4. The method of claim 1, wherein the plurality of groups of items
comprises individual columns of items aligned in the package.
5. The method of claim 1, wherein the plurality of groups of items
comprises individual rows of items aligned in the package.
6. The method of claim 1, wherein the plurality of groups of items
are arranged in a circular pattern.
7. The method of claim 1, wherein the plurality of groups of items
are randomly placed within the package.
8. The method of claim 1, wherein the reference signal corresponds
to a reflectance measurement.
9. The method of claim 1, wherein obtaining a signal corresponding
to each of the plurality of groups of items in the package is
accomplished by near infrared spectrographic analysis.
10. The method of claim 1, further comprising segregating the
groups of items that are non-conforming from the groups of items
that are conforming.
11. The method of claim 1, wherein determining whether any of the
plurality of groups of items is non-conforming comprises: computing
an average reflectance signal based on the reflectance signals
corresponding to each of the plurality of groups of items; and
comparing the average reflectance signal with the reference
reflectance signal.
12. The method of claim 11, wherein computing an average
reflectance signal comprises performing a first or second order
differencing function.
13. The method of claim 11, wherein computing an average
reflectance signal comprises performing a smoothing function.
14. The method of claim 1, wherein obtaining a data signal
corresponding to each of the plurality of groups of items in the
package comprises: obtaining an individual reflectance measurement
for each item in each of the plurality of groups of items; and
combining the individual reflectance measurements for each of the
plurality of groups of items.
15. A spectrographic inspection system for analyzing a package
containing a plurality of items, wherein the plurality of items is
arranged in an array having a column of items and a row of items,
the inspection system comprising; a first plurality of sample
probes, wherein each of the first plurality of sample probes
corresponds to an individual item location in the column of items;
a first spectrometer corresponding to the column of items, wherein
the first plurality of sample probes are coupled to the first
spectrometer; and a processor coupled to the first spectrometer,
wherein the processor is capable of being programmed to determine
whether an item in the package conforms to a predetermined
standard.
16. The inspection system of claim 15, further comprising: a second
plurality of sample probes, wherein each of the second plurality of
sample probes corresponds to an individual item location in the row
of items; and a second spectrometer corresponding to the row of
items, wherein the second plurality of sample probes are coupled to
the second spectrometer.
17. The inspection system of claim 15, wherein the pre-determined
standard is a known reflectance signal corresponding to the
plurality of items in the package.
18. The inspection system of claim 15, wherein the pre-determined
standard is a known signal programmed into the processor by a
user.
19. The inspection system of claim 15, wherein the pre-determined
standard is obtained by performing a calibration run on a package
containing items with a known reflectance signal.
20. The inspection system of claim 15, wherein the processor is
further capable of being programmed to determine which item in the
column of items is non-conforming.
21. The inspection system of claim 15, wherein the processor is
further capable of being programmed to determine which item in the
row of items is non-conforming.
22. The inspection system of claim 15, further comprising a
rejection unit coupled to the processor, wherein the rejection unit
is adapted to segregate the package depending on whether the
plurality of items in the package conform to the pre-determined
standard.
23. A fiber optic inspection manifold, comprising: a plurality of
sample probes arranged in a plurality of columns and a plurality of
rows; a plurality of column spectrometers, wherein each of the
plurality of column spectrometers corresponds to an individual
column of sample probes; a plurality of row spectrometers, wherein
each of the plurality of row spectrometers corresponds to an
individual row of sample probes; and a processor coupled to the
plurality of row spectrometers and the plurality of column
spectrometers.
24. The fiber optic inspection manifold of claim 23, wherein each
of the plurality of sample probes is adapted to gather
spectrographic information from an item and wherein the processor
is capable of being programmed to identify whether the item
conforms to a pre-determined standard.
25. The fiber optic inspection manifold of claim 24, wherein the
pre-determined standard is a known reflectance measurement.
26. An inspection system for verifying the contents of a package,
the package containing an array of items arranged in a plurality of
columns and a plurality of rows, the inspection system comprising:
a first plurality of sample probes coupled to a first spectrometer,
the first plurality of sample probes positioned to acquire data
corresponding to the items located in a column of the package; a
second plurality of sample probes coupled to a second spectrometer,
the second plurality of sample probes positioned to acquire data
corresponding to the items located in a row of the package.
27. The inspection system of claim 26, further comprising a
processor coupled to the first spectrometer and the second
spectrometer, the processor capable of being programmed to
determine whether any of the array of items conform to a
predetermined standard.
28. A method of inspecting a package containing a plurality of
groups of items, the method comprising: aligning the package with
an imaging spectrographic inspection station; directing light
energy at the plurality of groups of items; obtaining a reference
reflectance signal corresponding to a package containing conforming
items; acquiring an actual reflectance signal from each of the
plurality of groups of items in the package; comparing the actual
reflectance signal from each of the items with the reference
reflectance signal; determining whether the reflectance signal from
each of the items conforms to the reference reflectance signal;
rejecting the package if any of the individual item's reflectance
signals do not conform to the reference reflectance signal; and
accepting the package if all of the individual item's reflectance
signals conform to the reference reflectance signal.
29. The method of claim 28, wherein obtaining a reference
reflectance signal corresponding to a package containing conforming
items comprises inputting a known signal into the spectrographic
inspection station.
30. The method of claim 28, wherein obtaining a reference
reflectance signal corresponding to a package containing conforming
items comprises performing a calibration run on a package
containing only conforming items.
31. A method of identifying non-conforming groups of items within a
package, the package containing a plurality of groups of items, the
method comprising: means for obtaining a reference signal
corresponding to a conforming package; means for obtaining a signal
corresponding to each of the plurality of groups of items in the
package; means for comparing the signal corresponding to each of
the plurality of groups of items with the reference signal; means
for determining whether any of the plurality of groups of items is
non-conforming; and means for segregating the package based on
whether the package contains a non-conforming group of items.
32. The method of claim 31, further comprising means for
segregating the groups of items that contain a non-conforming item
from the groups of items that do not contain a non-conforming item.
Description
[0001] The present application claims priority to U.S. provisional
application No. 60/268,483 and titled NIR Screening of Materials To
Be Packaged, filed on Feb. 12, 2001, which is hereby incorporated
by reference.
RELATED APPLICATIONS
[0002] The present application is based on disclosure document No.
481228 deposited with the U.S. Patent and Trademark Office on Oct.
17, 2000. The present application is also related to U.S. patent
application No. [Cooley Godward docket No. ASDI-003/00US], filed on
even date herewith and titled System and Method for Combining
Reflectance Data, and U.S. patent application No. [Cooley Godward
docket No. ASDI005/00US], filed on even date herewith and titled
System and Method for the Collection of Spectral Image Data. Each
of the above documents are hereby incorporated by reference.
FIELD OF THE INVENTION
[0003] The present invention pertains to spectrometer and
reflectance data analysis and more particularly to the screening
and identification of materials such as pharmaceutical or food
products being packaged in an automated machine.
BACKGROUND OF THE INVENTION
[0004] Optical spectrometers allow the study of a large variety of
samples over a wide range of wavelengths. Materials can be studied
in the solid, liquid, or gas phase either in a pure form or in
mixtures. Various designs allow the study of spectra as a function
of temperature, pressure, and external magnetic fields.
[0005] Near-Infrared (NIR) spectroscopy is one of the most rapidly
growing methodologies in product analysis and quality control. In
particular, NIR is being increasingly used as an inspection method
during the packaging process of pharmaceuticals or food products.
More and more often, this technique is augmenting or even replacing
previously used vision inspection systems. For example, an NIR
inspection system can be used to inspect a pharmaceutical blister
package (such as an oral contraceptive or allergy medication) for,
among other things, physical aberrations, chemical composition,
moisture content, and proper package arrangement.
[0006] Most notably, NIR spectrometry inspection systems can be
used to evaluate the chemical composition of products during the
packaging process. Particularly with solid dosage pharmaceutical
products, a group or package of products may look identical in the
visible portion of the spectrum but may have unique chemical
signatures in the near-infrared range (e.g. the 800-2500 nm range).
Variations in the chemical composition of a tablet or capsule are
usually grounds for rejecting a package containing a tablet with
such a discrepancy. In operation on a pharmaceutical blister
packaging machine, a still uncovered blister pack containing
tablets or capsules passes an inspection station where it is
examined. Once the inspection device inspects the blister pack to
ensure that the correct material is located in each of the tablet
or capsule wells, the packaging machine seals the blister pack.
Those packages that fail the inspection process are rejected at a
subsequent station. Subject to regulatory requirements, the
rejected tablets may also be recycled for further processing.
[0007] The use of vision systems as an inspection mechanism
continues to become less desirable as the need for more in depth
inspection procedures and near 100% inspection processes are
desired. Of particular concern is that known vision systems are
inherently incapable of performing a chemical analysis of the
product being packaged. Rather, vision systems rely solely on a
comparison of a visual snapshot of the package to a previously
stored reference image. Known vision packaging inspection systems
"look" at each individual package to see whether it has the correct
number of doses in the pack. For example, vision systems look for
missing or overfilled tablet wells. In some cases, physical
discrepancies, cracks, or gouges on a tablet will also cause a
vision system to reject the package. What may not be detected by a
vision system is the situation where each of the products in a
package appears to be similar and in conformance with a reference
image but the formulation of one or more products within the
package are incorrect, or the wrong product composition is inserted
into the packaging. The limitations of these types of known visions
systems become readily apparent when higher levels of inspection
are required and when they are compared with the expanded
capabilities of a spectrometer-based inspection system.
[0008] Even though spectrometer-based monitoring and inspection
systems are becoming more prevalent, many of them still have
limited capabilities. These limitations are primarily due to the
requirement that each tablet or capsule in a package be
independently inspected by the spectrometer system. Therefore, a
conventional spectrometer can only look at and analyze one sample
at a time. Thus, the larger the number of products that are being
inspected, the longer it will take to perform the inspection.
Adding additional spectrometers is not a preferred solution because
of the costs and maintenance issues associated with the increased
hardware. Since spectrometer-based systems are meant in large part
to replace vision systems, both accuracy and speed remain important
factors when utilizing such systems. Thus, it would be desirable to
have a spectrometer-based inspection system that can maintain the
throughput of traditional vision systems without sacrificing the
ability to perform accurate chemical composition analysis and
without requiring the addition of expensive and problem prone
equipment.
[0009] In many cases, multiple formulations are packaged into a
single blister pack. Therefore, it is also desirable to have a
spectrometer-based inspection system that can detect when an item
is in the wrong location within the larger package that is being
inspected while at the same time realizing the benefits of a
spectrometer based inspection system.
[0010] Finally, it is desirable to have a spectrometer-based
inspection system that can execute a self-referencing calibration
in order to obtain conforming data to compare with during an
inspection process as well as to determine item locations from a
previously unknown package layout.
SUMMARY OF THE INVENTION
[0011] In one aspect, a method of identifying non-conforming groups
of items within a package, the package containing a plurality of
groups of items, comprises obtaining a reference signal
corresponding to a package containing conforming groups of items,
obtaining a signal corresponding to each of the plurality of groups
of items in the package, comparing the signal corresponding to each
of the plurality of groups of items with the reference signal,
determining whether any of the plurality of groups of items is
non-conforming, and segregating the package based on whether the
package contains a non-conforming group of items.
[0012] In another aspect, a spectrographic inspection system for
analyzing a package containing a plurality of items, wherein the
plurality of items is arranged in an array having a column of items
and a row of items, comprises a first plurality of sample probes,
wherein each of the first plurality of sample probes corresponds to
an individual item location in the column of items, a first
spectrometer corresponding to the column of items, wherein the
first plurality of sample probes are coupled to the first
spectrometer, and a processor coupled to the first spectrometer,
wherein the processor is capable of being programmed to determine
whether an item in the package conforms to a predetermined
standard.
[0013] In yet a further aspect, a fiber optic inspection manifold
comprises a plurality of sample probes arranged in a plurality of
columns and a plurality of rows, a plurality of column
spectrometers, wherein each of the plurality of column
spectrometers corresponds to an individual column of sample probes,
a plurality of row spectrometers, wherein each of the plurality of
row spectrometers corresponds to an individual row of sample
probes, and a processor coupled to the plurality of row
spectrometers and the plurality of column spectrometers.
[0014] In still a further aspect an inspection system for verifying
the contents of a package, the package containing an array of items
arranged in a plurality of columns and a plurality of rows,
comprises a first plurality of sample probes coupled to a first
spectrometer, the first plurality of sample probes positioned to
acquire data corresponding to the items located in a column of the
package, and a second plurality of sample probes coupled to a
second spectrometer, the second plurality of sample probes
positioned to acquire data corresponding to the items located in a
row of the package.
[0015] In another aspect, a method of inspecting a package
containing a plurality of groups of items comprises aligning the
package with an imaging spectrographic inspection station,
directing light energy at the plurality of groups of items,
obtaining a reference reflectance signal corresponding to a package
containing conforming items, acquiring an actual reflectance signal
from each of the plurality of groups of items in the package,
comparing the actual reflectance signal from each of the items with
the reference reflectance signal, determining whether the
reflectance signal from each of the items conforms to the reference
reflectance signal, rejecting the package if any of the individual
item's reflectance signals do not conform to the reference
reflectance signal, and accepting the package if all of the
individual item's reflectance signals conform to the reference
reflectance signal.
[0016] As will become apparent to those skilled in the art,
numerous other embodiments and aspects will become evident
hereinafter from the following descriptions and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The drawings illustrate both the design and utility of the
preferred embodiments of the present invention, wherein:
[0018] FIG. 1 is a general overview of an inspection system;
[0019] FIG. 2 is a diagram of a first embodiment of an inspection
head constructed in accordance with the present invention;
[0020] FIG. 3 is a schematic representation of the inspection head
of FIG. 2;
[0021] FIG. 4 is a diagram of a second embodiment of an inspection
head constructed in accordance with the present invention;
[0022] FIG. 5 is a schematic representation of the inspection head
of FIG. 4;
[0023] FIG. 6 is a diagram of a further embodiment of an inspection
head constructed in accordance with the present invention;
[0024] FIG. 7 is a schematic representation of the inspection head
of FIG. 6;
[0025] FIG. 8 is a diagram of a light energy aggregator constructed
in accordance with an embodiment of the present invention;
[0026] FIGS. 9-12 are details of a splitter block constructed in
accordance with an embodiment of the present invention;
[0027] FIGS. 13-15 are perspective diagrams of an inspection head
constructed in accordance with various aspects of the present
invention;
[0028] FIGS. 16 and 17 are flow charts depicting inspection methods
in accordance with various embodiments of the present
invention;
[0029] FIG. 18 is a cross-section of a scanning spectrometer system
constructed in accordance with an embodiment of the present
invention;
[0030] FIGS. 19A-19C are plan views of a package at various stages
of an inspection system constructed in accordance with an
embodiment of the present invention; and
[0031] FIG. 20 is a flow chart depicting a method in accordance
with an embodiment of the present invention.
DETAILED DESCRIPTION
[0032] FIG. 1 depicts an inspection system 100. The inspection
system 100 is generally arranged to allow the inspection of a
product, for example tablets or capsules 130, that have been loaded
into a package 125. As shown in FIG. 1, the packages 125 move along
a conveyer 120 mounted within a filling unit 105. The filling unit
105 is preferably one component of a larger manufacturing and
packaging system. As an example, such manufacturing and packaging
systems are typically utilized in pharmaceutical and chemical
manufacturing facilities, although similar systems are often
utilized in other applications such as food processing and consumer
product facilities. Aspects of the present invention can be applied
to virtually any of these applications. For purposes of
illustration only, the present invention will be described in
conjunction with a pharmaceutical packaging system used to seal
tablets or capsules in a blister-type package. Also shown in FIG.
1, and included as a component of the inspection system 100, is an
inspection head 110 constructed in accordance with various aspects
of the present invention.
[0033] The inspection head 110 bridges the conveyer 120 that
carries the packages 125. The inspection head 110 includes an array
of sample probes 115 extending downward from the inspection head
110 and substantially aligning with the items 130 contained in the
passing packages 125. Generally, a light source (not shown)
illuminates the packages 125 including the tablets 130 as they pass
under the inspection head 110 and the sample probes 115. Light is
reflected by the tablets 130 and the reflected light energy is
gathered by one or more of the probes 115. In the general
arrangement of FIG. 1, a single sample probe 115 corresponds to a
single tablet. Either the web of packages 125 moves in steps, where
the step increment matches the size of the packages in the
direction of motion, or the web moves continuously. In the stepped
progression, item inspection occurs when the package web is
stationary. In the continuous progression, item inspection occurs
during the time interval when the items are in the field of view of
the probes 115. As discussed below, various other arrangements of
the sample probes are contemplated by an inspection system
constructed in accordance with the present invention.
[0034] The reflected light energy gathered by each of the probes
115 is analyzed to determine specific properties of each of the
tablets 130 that pass beneath the inspection head 110. Light energy
gathered by the sample probes 115 is then directed through fiber
optic cables, to a spectrometer that may be housed within the
inspection head 110 (not shown). The collected light energy is
analyzed by the spectrometer according to predetermined criteria.
The information generated by the spectrometer is then forwarded via
a data cable 140 to a computer 135 for display, storage, or further
analysis. The computer 135 may be preloaded with processing
information pertaining to the specific packaging or inspection
operation being conducted. The information gathered about the
tablets 130 contained in each package 125 may then be used to
determine whether the specific tablets being inspected conform with
a predetermined quality criteria.
[0035] By gathering spectrographic data about each of the tablets
130, a determination can be made as to whether the packages have
been properly filled or contain the proper product. Spectrographic
analysis also allows other determinations to be made that are not
available with known vision-based systems, such as proper
pharmacological composition, water content, and other chemical and
physical properties.
[0036] FIG. 2 shows in further detail a diagrammatic representation
of a lower portion of the inspection head 110, and more
particularly, the array of sample probes and how they interact with
the tablets passing along the conveyer 120. The probe array is
generally referred to in FIG. 2 as reference number 200. In the
example of FIG. 2, a product package 215, such as a filled but yet
un-sealed blister package, contains fifteen (15) individual tablets
in a three-by-five arrangement. Various other arrangements of the
tablets are contemplated and the three-by-five arrangement of FIG.
2 is shown merely as an example. The tablets in the package 215 are
arranged into five columns. From left to right in FIG. 2, column
one includes tablets 225a, 225b, and 225c, column two contains
tablets 230a, 230b, and 230c, column three contains tablets 235a,
235b, and 235c, column four contains tablets 240a, 240b, and 240c,
and column five contains tablets 245a, 245b, and 245c.
Corresponding to each of the fifteen tablets in FIG. 2 is a sample
probe. From left to right, the sample probes also are divided into
five columns with three sample probes in each column. Column one
contains sample probes 325a, 325b, and 325c, column two contains
sample probes 330a, 330b, and 330c, column three contains sample
probes 335a, 335b, and 335c, column four contains sample probes
340a, 340b, and 340c, and column five contains sample probes 345a,
345b, and 345c. As the conveyer system moves the package 215 into
position under the inspection head 110, the fifteen sample probes
are positioned to correspond respectively to a similarly positioned
tablet in the package 215. Namely, the sample probes are positioned
substantially above the correspondingly positioned tablet.
[0037] Each of the sample probes are connected to a fiber optic
cable which in turn is connected to a light energy aggregator 350.
In FIG. 2, the fifteen fiber optic cables are represented as
reference numbers 250, 255, 260, 265, 270, 275, 280, 285, 290, 295,
300, 305, 310, 315, and 320. Each one of the fiber optic cables
corresponds to a single sample probe and thus also corresponds to a
light reading from the corresponding tablet passing beneath the
inspection head.
[0038] The light energy aggregator 350 operates to combine the
light energy gathered by each of the fifteen sample probes (via the
fiber optic cables) and output the combined light energy through a
single output terminal. Further details of a preferred embodiment
of a light energy aggregator constructed in accordance with the
present invention are described in conjunction with FIGS. 8-12.
Briefly, the combined light energy from the light energy aggregator
350 is directed to an entrance slit on a spectrometer 355 where it
is subsequently analyzed. Light sources 220a and 220b illuminate
the tablets as they pass beneath the sample probes.
[0039] In operation, the inspection head allows a system to
evaluate whether any of the fifteen tablets in the package 215 are
misplaced, defective, missing, chemically nonconforming, or have
another problem, while utilizing a single spectrometer 355. As the
packaging system begins a run, reflectance data is acquired from a
known representative sample package of tablets as it passes beneath
the tips of the sample probes, and statistics are compiled based on
the combined spectra of the items being inspected. The
representative package is of a known quality, and this initial run
is thus classified as a calibration run. Appropriate preprocessing
of the spectra such as smoothing or first or second differencing is
applied. During the normal inspection process associated with a
packaging run, the spectrum of each group or package of tablets is
compared back to the representative spectra collected during the
calibration run. This comparison may be through principal component
analysis in which the first two or more eigenvectors are calculated
and applied to the spectrum of each group of inspected items.
Another comparison method relies on the dot product between the
vector containing values from each of the spectral wavelength
channels in the calibration run and the spectral vector of the
package to be inspected. Any spectrum that deviates in its totality
by more than a specified number of standard deviations is deemed to
contain foreign material and a signal is sent to the packaging
machine causing the group of items/package in question to be
rejected and removed from the line before final packaging. Further
details of spectra comparisons, as well as other methods of
comparison, can be found in the Handbook of Near-Infrared Analysis,
Donald Bums and Emil W. Ciurczak, Marcel Dekker, Inc. 1992, the
details of which are hereby incorporated by reference into the
present application. Alternately, if reflectance values are known
for a particular item or package, this information can be input
directly into the inspection system and a calibration run becomes
unnecessary.
[0040] Turning to FIG. 3, a schematic diagram of an inspection
system 400 constructed in accordance with the present invention is
shown. The schematic diagram of FIG. 3 generally corresponds to
FIG. 2. The diagram of FIG. 3 represents how a number of different
sample probes P.sub.1-P.sub.N can be utilized to obtain a
spectrographic measurement from any number of individual samples
and feed the collected information to a single spectrometer as a
combined input. Based on the combined reading from all of the
sample probes, an evaluation can be made as to whether a defect
(either chemical or physical) exists somewhere in the package.
Since a combined value is obtained, the package as a whole is
analyzed for a defect rather than each particular tablet. If the
package as a whole is determined to have a defect, that entire
package can be rejected. Utilizing such a system allows faster
analysis while utilizing a single spectrometer thereby making the
system as a whole less expensive and easier to maintain.
[0041] With continuing reference to FIG. 3, Each of the sample
probes P.sub.1 through P.sub.n, represented by reference numbers
405, 410, 415, 420, 425, 430, 435, 440, and 445 are connected to a
fiber optic cable, shown as reference numbers 407, 412, 417, 422,
427, 432, 437, 442, and 447 respectively. The fiber optic cables
are, in turn, connected to a light energy aggregator 450. The light
energy aggregator 450 operates to combine the light energy gathered
by each of the fiber optic cables and output the combined light
energy through a single output terminal. Further details of a
preferred embodiment of a light energy aggregator constructed in
accordance with the present invention are described in conjunction
with FIGS. 8-12. Briefly, and as shown in FIG. 3, the combined
output light energy from the light energy aggregator 450 is
directed through a single fiber optic cable 455 and through an
entrance slit 457 of a spectrometer 460. The combined light energy
is subsequently analyzed by the spectrometer 460. A processor 465
is coupled to the spectrometer 460 and further analyzes the
combined light energy received by the spectrometer 460. The
processor 465 then compares these results to a pre-determined or
pre-assigned value that represents an acceptable measurement of the
package (i.e. a package without an unacceptable level of defects).
The comparison value can either be obtained by a calibration run as
described above or can be input into the processor based on known
values. If the defect level does not conform to the comparison
value, a rejection unit 470 coupled to the processor sends a signal
to the packaging line to discard or remove the package with the
defect.
[0042] The embodiment of the inspection system of FIGS. 2 and 3
utilizes a single spectrometer to analyze the collective samples of
fifteen different sample probes and thus can reject or accept a
package based on whether the package spectra as a whole meets a
pre-determined criteria. As mentioned above, the use of a single
spectrometer to evaluate the conformance of an entire package of
tablets increases the speed of the inspection process while
simultaneously reducing the cost of such an inspection system.
However, the system of FIGS. 2 and 3 is unable to distinguish the
precise location within the package of the foreign substance or
damaged tablet. Often, it is desired to more accurately and
precisely locate the non-conforming tablet(s) from within each
package.
[0043] Turning to FIG. 4, a diagrammatic representation of an
inspection system constructed in accordance with a further aspect
of the present invention is shown. FIG. 4 shows in further detail a
diagrammatic representation of the lower portion of an inspection
head 110 used in conjunction with an inspection system, and more
particularly, an array of sample probes and how they interact with
the tablets passing along a conveyer. The probe array is generally
referred to in FIG. 4 as reference number 500. In the example of
FIG. 4, a product package 515, such as a filled but yet un-sealed
blister package, contains fifteen (15) individual tablets in a
three-by-five arrangement. Various other arrangements of the
tablets are contemplated and the three-by-five arrangement of FIG.
4 is shown merely as an example. The tablets in the package 215 are
arranged into five rows. From left to right in FIG. 4, column one
includes tablets 525a, 525b, and 525c, column two contains tablets
530a, 530b, and 530c, column three contains tablets 535a, 535b, and
535c, column four contains tablets 540a, 540b, and 540c, and column
five contains tablets 545a, 545b, and 545c. Corresponding to each
of the fifteen tablets in FIG. 2 is a sample probe. From left to
right, the sample probes also are divided into five columns with
three sample probes in each column. Column one contains sample
probes 625a, 625b, and 625c, column two contains sample probes
630a, 630b, and 630c, column three contains sample probes 635a,
635b, and 635c, column four contains sample probes 640a, 640b, and
640c, and column five contains sample probes 645a, 645b, and 645c.
As the conveyer system moves the package 515 into position under
the inspection head 110, the fifteen sample probes are positioned
to correspond respectively to a similarly positioned tablet in the
package 515. Namely, the samples probes are positioned
substantially above the correspondingly positioned tablet.
[0044] Each of the sample probes are connected to a fiber optic
cable which in turn is connected to one of five different light
energy aggregators 650, 660, 670, 680, or 690. In FIG. 4, the
fifteen fiber optic cables are represented as reference numbers
550, 555, 560, 565, 570, 575, 580, 585, 590, 595, 600, 605, 610,
615, and 620. Each one of-the fiber optic cables corresponds to a
single sample probe and thus also corresponds to a light reading
from the corresponding tablet passing beneath the inspection
head.
[0045] Each of the light energy aggregators 650, 660, 670, 680, and
690 operates to combine the light energy gathered by the three
sample probes (via the fiber optic cables) that feed light energy
into it. Each light energy aggregator then outputs the combined
light energy through a single output terminal. In the embodiment of
FIG. 4, each of the light energy aggregators 650, 660, 670, 680,
and 690 is associated with the fiber optic cables and sample probes
from a single column. More specifically, light energy aggregator
650 receives light energy input from fiber optic cables 550, 555,
and 560, light energy aggregator 660 receives light energy input
from fiber optic cables 565, 570, and 575, light energy aggregator
670 receives light energy input from fiber optic cables 580, 585,
and 590, light energy aggregator 680 receives light energy input
from fiber optic cables 595, 600, and 605, and light energy
aggregator 690 receives light energy input from fiber optic cables
610, 615, and 620. Further details of a preferred embodiment of a
light energy aggregator constructed in accordance with the present
invention are described in conjunction with FIGS. 8-12. Briefly,
the combined light energy from each of the light energy
aggregator's 650, 660, 670, 680, and 690 is directed to an entrance
slit on a corresponding spectrometer 655, 665, 675, 685, or 695
where it is subsequently analyzed. Light sources 520a and 520b
illuminate the tablets as they pass beneath the sample probes.
[0046] In operation, the inspection head allows a system to
evaluate whether one or more of the fifteen tablets in the package
515 are misplaced, defective, missing, chemically non-conforming,
or otherwise non-conforming. As the packaging system begins a run,
reflectance data is acquired from a known representative sample
package of tablets as they pass beneath the tips of the sample
probes and statistics are compiled based on the combined spectra of
the items being inspected. The representative package is of a known
quality and this initial run is thus classified as a calibration
run. Preprocessing of the spectra is applied in a similar manner as
described above in conjunction with FIG. 2, however, information is
gathered on a column-by-column basis rather than on a
whole-package-basis as in the embodiment of FIG. 2. In this manner,
if a defect or other abnormality is discovered within the package
515, the location of the defect can be narrowed down to a
particular column within the package allowing segregation of the
defective component and allowing more of the conforming tablets to
be reused in the packaging run. Less waste and higher throughput is
therefore realized.
[0047] Similarly, where blister packs contain more than one
formulation, e.g. the package in FIG. 4 could have up to 5
formulations (one in each row), the system would be able to detect
a misplaced tablet in any of the columns. Single spectrometer
systems would not be able to detect when a tablet in one row got
inadvertently switched with a tablet in a second row having a
different formulation. Probes from the multiple spectrometer system
of FIG. 4 can be arranged in any configuration and not just in rows
as shown.
[0048] Turning to FIG. 5, a schematic diagram of an inspection
system 700 constructed in accordance with the present invention is
shown. The schematic diagram of FIG. 5 generally corresponds to
FIG. 4. The diagram of FIG. 5 represents how a number of different
sample probes P.sub.A1-P.sub.E3 can be utilized to obtain a
spectrographic measurement from any number of individual samples on
a column-by-column basis and feed the collected column-by-column
information through a column specific light energy aggregator to a
column-specific spectrometer as a combined input. Based on the
combined reading from the sample probes in each row, an evaluation
can be made as to whether a defect (either chemically or
physically) exists somewhere in the package. In the case of a
blister package containing tablets with several different
formulations, groups of probes feeding light to each of the light
energy aggregators are positioned above the groups of tablets
having a single formulation. A further determination can be made as
to which column the defect or other abnormality resides. Since a
combined value is obtained for each column of tablets, a particular
column as a whole is analyzed for a defect rather than each
particular tablet. Thus, the system can detect when tablets with a
given formulation are placed in the wrong row. In many cases, any
such formulation misplacement will cause the entire package to be
rejected, however, it is contemplated that the otherwise conforming
tablets can be salvaged and stored for later reuse or can be
automatically placed back into the packaging line for inclusion in
a subsequent package. Utilizing such a system allows faster
analysis while requiring a fewer number of spectrometers thereby
making the system as a whole less expensive and easier to
maintain.
[0049] With continuing reference to FIG. 5, each of the sample
probes P.sub.A1 through P.sub.E3, represented by reference numbers
702, 704, 706, 708, 710, 712, 714, 716, 718, 720, 722, 724, 726,
728, and 730 are connected to a corresponding fiber optic cable,
shown as reference numbers 732, 734, 736, 738, 740, 742, 744, 746,
748, 750, 752, 754, 756, 758, and 760 respectively. The subscript
designation in each of the probe labels refers to the column and
row of each sample probe respectively. Namely, the letter
designations, A, B, C, etc. refer to the first, second, third, etc.
columns while the number designations 1, 2, and 3, refer to the row
designation in each column. Each one of the array of fifteen sample
probes can therefore be uniquely represented.
[0050] The column-by-column groupings of fiber optic cables are in
turn connected to a corresponding light energy aggregator 762, 764,
766, 768, or 770. Each of the light energy aggregators operate to
combine the light energy gathered by the fiber optic cables from a
particular column and output the combined light energy through a
single output terminal. Further details of a preferred embodiment
of a light energy aggregator constructed in accordance with the
present invention are described in conjunction with FIGS. 8-12.
Briefly, and as shown in FIG. 5, the combined output light energy
from the light energy aggregator 762 is directed through a single
fiber optic cable 771 and through an entrance slit 763 of a
spectrometer 772. The combined light energy is subsequently
analyzed by the spectrometer 772. The combined output light energy
from the light energy aggregator 764 is directed through a single
fiber optic cable 773 and through an entrance slit 765 of a
spectrometer 774. The combined light energy is subsequently
analyzed by the spectrometer 774. The combined output light energy
from the light energy aggregator 766 is directed through a single
fiber optic cable 775 and through an entrance slit 767 of a
spectrometer 776. The combined light energy is subsequently
analyzed by the spectrometer 776. The combined output light energy
from the light energy aggregator 768 is directed through a single
fiber optic cable 777 and through an entrance slit 769 of a
spectrometer 778. The combined light energy is subsequently
analyzed by the spectrometer 778. The combined output light energy
from the light energy aggregator 770 is directed through a single
fiber optic cable 779 and through an entrance slit 781 of a
spectrometer 780. The combined light energy is subsequently
analyzed by the spectrometer 780.
[0051] A processor 790 is coupled to each of the five spectrometers
772, 774, 776, 778, and 780 by data cables 782, 784, 786, 788, and
789 and further analyzes the combined light energy received by the
spectrometers. The processor 790 then compares these results to a
pre-determined or pre-assigned value that represents an acceptable
measurement of the package (i.e. a package with an acceptable level
of defects). The comparison value can either be obtained by a
calibration run as described above or can be input into the
processor based on known values. If the defect level does not
conform to the comparison value, a rejection unit 794 coupled to
the processor sends a signal to the packaging line to discard or
remove the package with the defect.
[0052] Turning to FIG. 6, a diagrammatic representation of a
further aspect of an inspection system constructed in accordance
with the present invention is shown. FIG. 6 shows in further detail
a diagrammatic representation of the lower portion of an inspection
head 110 used in conjunction with an inspection system, and more
particularly, an array of sample probes and how they interact with
the tablets passing along a conveyer. The probe array is generally
referred to in FIG. 6 as reference number 800. In the example of
FIG. 6, a product package 815, such as a filled but yet un-sealed
blister package, contains fifteen (15) individual tablets in a
three-by-five arrangement. Various other arrangements of the
tablets are contemplated and the three-by-five arrangement of FIG.
6 is shown merely as an example. The tablets in the package 815 are
arranged into five columns, each having three rows. From left to
right in FIG. 6, column one includes tablets 825a, 825b, and 825c,
column two contains tablets 830a, 830b, and 830c, column three
contains tablets 835a, 835b, and 835c, column four contains tablets
840a, 840b, and 840c, and column five contains tablets 845a, 845b,
and 845c. Corresponding to each of the fifteen tablets in the
example of FIG. 6 is a sample probe. From left to right, the sample
probes are also divided into five columns with three sample probes
in each column. Column one contains sample probes 925a, 925b, and
925c, column two contains sample probes 930a, 930b, and 930c,
column three contains sample probes 935a, 935b, and 935c, column
four contains sample probes 940a, 940b, and 940c, and column five
contains sample probes 945a, 945b, and 945c. As the conveyer system
moves the package 815 into position under the inspection head 110,
the fifteen sample probes are positioned to correspond respectively
to a similarly positioned tablet in the package 815. Namely, the
samples probes are positioned substantially above the
correspondingly positioned tablet.
[0053] Each of the sample probes are connected to a pair of fiber
optic cables which in turn are connected to one of five different
column light energy aggregators 950, 960, 970, 980, or 990 and to
one of three different row light energy aggregators 1080, 1090, or
1100. Thus, each sample probe is connected to one column light
energy aggregator and to one row light energy aggregator. In FIG.
6, the thirty fiber optic cables connecting the sample probes to
the eight light energy aggregator are represented as reference
numbers 850, 855, 860, 865, 870, 875, 880, 885, 890, 895, 900, 905,
910, 915, 920 (corresponding to the column light energy
aggregators), 1000, 1005, 1010, 1015, 1020, 1025, 1030, 1035, 1040,
1045, 1050, 1055, 1060, 1065, and 1070 (corresponding to the row
light energy aggregators). Each one of these thirty fiber optic
cables corresponds to a single sample probe and thus also
corresponds to a light reading from a single tablet passing beneath
the inspection head. Since there are two fiber optic cables for
each sample probe, a reading from a particular sample probe is
passed to both a column light energy aggregator and to a row light
energy aggregator.
[0054] Each of the light energy aggregators 950, 960, 970, 980,
990, 1080, 1090, and 1100 operate to combine the light energy
gathered by the sample probes (via the fiber optic cables) that
feed light energy into it. Each light energy aggregator then
outputs the combined light energy through a single output terminal.
In the embodiment of FIG. 6, each of the light energy aggregators
950, 960, 970, 980, and 990 is associated with the fiber optic
cables and sample probes from a single column, while each of the
light energy aggregators 1080, 1090, and 1100 is associated with
the fiber optic cables and sample probes from a single row. More
specifically, light energy aggregator 950 receives light energy
input from fiber optic cables 850, 855, and 860, light energy
aggregator 960 receives light energy input from fiber optic cables
865, 870, and 875, light energy aggregator 970 receives light
energy input from fiber optic cables 880, 885, and 890, light
energy aggregator 980 receives light energy input from fiber optic
cables 895, 900, and 905, and light energy aggregator 9 90 receives
light energy input from fiber optic cables 910, 915, and 920. Light
energy aggregator 1080 receives light energy input from fiber optic
cables 1000, 1005, 1010, 1015, and 1020, light energy aggregator
1090 receives light energy input from fiber optic cables 1025,
1030, 1035, 1040, and 1045, and light energy aggregator 1100
receives light energy input from fiber optic cables 1050, 1055,
1060, 1065, and 1070.
[0055] Further details of a preferred embodiment of a light energy
aggregator constructed in accordance with the present invention are
described in conjunction with FIGS. 8-12. Briefly, the combined
light energy from each of the light energy aggregators 950, 960,
970, 980, 990, 1080, 1090, and 1100 is directed to an entrance slit
on a corresponding spectrometer 955, 965, 975, 985, 995, 1085,
1095, or 1105 where it is subsequently analyzed. Light sources 820a
and 820b illuminate the tablets as they pass beneath the sample
probes.
[0056] In operation, the inspection head allows a system to
evaluate whether one of the fifteen tablets in the package 815 are
misplaced, defective, missing, chemically nonconforming, or has
another problem. As the packaging system begins a run, reflectance
data is acquired from a known representative sample package of
tablets as they pass beneath the tips of the sample probes and
statistics are compiled based on the combined spectra of the items
being inspected. The representative package is of a known quality
and this initial run is thus classified as a calibration run.
Preprocessing of the spectra is applied in a similar manner as
described above in conjunction with FIG. 2, however, information is
gathered on a column-by-column and row-by-row basis rather than on
a whole-package-basis as in the embodiment of FIG. 2. In this
manner, if a defect or other abnormality is discovered within the
package 815, the location of the defect can be narrowed down to a
particular row and a particular column within the package allowing
precise segregation of the defective component and allowing all of
the conforming tablets to be utilized in a subsequent packaging
run. Less waste and higher throughput is therefore realized.
[0057] Turning to FIG. 7, a schematic diagram of an inspection
system 1200 constructed in accordance with the present invention is
shown. The schematic diagram of FIG. 7 generally corresponds to
FIG. 6. The diagram of FIG. 7 represents how a number of different
sample probes P.sub.A1-P.sub.E3 can be utilized to obtain a
spectrographic measurement from any number of individual samples on
a row-by-row and column-by-column basis. The collected row
information is fed through a row specific light energy aggregator
to a row-specific spectrometer as a combined input and the
collected column information is fed through a column specific light
energy aggregator to a column-specific spectrometer as a combined
input. Based on the combined reading from the sample probes
corresponding to each row and the sample probes corresponding to
each column, an evaluation can be made as to whether a defect
(either chemical or physical) exists somewhere in the package. A
further determination can be made as to which row and column the
defect or other abnormality resides, and therefore, the precise
location of the non-conforming item can be ascertained. Since a
combined value is obtained for each row and column of tablets, a
particular row as a whole or a particular column as a whole is
analyzed for a defect rather than each particular tablet. If a
particular row or particular column as a whole is determined to
have a defect, the entire package can be rejected but the
conforming tablets can be salvaged and stored for later reuse or be
automatically placed back into the packaging line for insertion
into a subsequent package. Utilizing such a system allows faster
analysis while utilizing a fewer number of spectrometers thereby
making the system as a whole less expensive and easier to
maintain.
[0058] With continuing reference to FIG. 7, each of the fifteen
sample probes P.sub.A1 through P.sub.E3, represented by reference
numbers 1202, 1204, 1206, 1208, 1210, 1212, 1214, 1216, 1218, 1220,
1222, 1224, 1226, 1228, and 1230 are connected to a pair of
corresponding fiber optic cables. The fiber optic cables
corresponding to the five columns of sample probes are shown as
reference numbers 1232, 1234, 1236, 1238, 1240, 1242, 1244, 1246,
1248, 1250, 1252, 1254, 1256, 1258, and 1260 respectively. The
fiber optic cables corresponding to the three rows of sample probes
are shown as reference numbers 1302, 1304, 1306, 1308, 1310, 1312,
1314, 1316, 1318, 1320, 1322, 1324, 1326, 1328, and 1330
respectively. The subscript designation in each of the probe labels
refer to the column and row of each probe. Namely, the letter
designations, A, B, C, etc. refer to the first, second, third, etc.
columns and the number designations 1, 2, and 3 refer to the row
designation in each column. Each of the array of fifteen sample
probes can thus be uniquely represented.
[0059] The column-by-column grouping of fiber optic cables are
connected to a corresponding column light energy aggregator 1262,
1264, 1266, 1268, and 1270, and the row-by-row groupings of fiber
optic cables are in turn connected to a corresponding row light
energy aggregator 1332, 1334, and 1336. Each of the light energy
aggregators operate to combine the light energy gathered by the
fiber optic cables from a particular column or row and output the
combined light energy through a single output terminal. Further
details of a preferred embodiment of a light energy aggregator
constructed in accordance with the present invention are described
in conjunction with FIGS. 8-12. Briefly, and as shown in FIG. 7,
the combined output light energy from the column light energy
aggregator 1262 is directed through a single fiber optic cable 1272
and through an entrance slit 1273 to a spectrometer 1282. The
combined light energy is subsequently analyzed by the spectrometer
1282. The combined output light energy from the column light energy
aggregator 1264 is directed through a single fiber optic cable 1274
and through an entrance slit 1275 to a spectrometer 1284. The
combined light energy is subsequently analyzed by the spectrometer
1284. The combined output light energy from the column light energy
aggregator 1266 is directed through a single fiber optic cable 1276
and through an entrance slit 1277 to a spectrometer 1286. The
combined light energy is subsequently analyzed by the spectrometer
1286. The combined output light energy from the column light energy
aggregator 1268 is directed through a single fiber optic cable 1278
and through an entrance slit 1279 to a spectrometer 1288. The
combined light energy is subsequently analyzed by the spectrometer
1288. The combined output light energy from the column light energy
aggregator 1270 is directed through a single fiber optic cable 1280
and through an entrance slit 1281 to a spectrometer 1290. The
combined light energy is subsequently analyzed by the spectrometer
1290.
[0060] Similarly, the combined output light energy from the row
light energy aggregator 1332 is directed through a single fiber
optic cable 1338 and through an entrance slit 1339 to a
spectrometer 1344. The combined light energy is subsequently
analyzed by the spectrometer 1344. The combined output light energy
from the row light energy aggregator 1334 is directed through a
single fiber optic cable 1340 and through an entrance slit 1341 to
a spectrometer 1346. The combined light energy is subsequently
analyzed by the spectrometer 1346. The combined output light energy
from the row light energy aggregator 1336 is directed through a
single fiber optic cable 1342 and through an entrance slit 1343 to
a spectrometer 1348. The combined light energy is subsequently
analyzed by the spectrometer 1348.
[0061] A processor 1360 is coupled to each of the eight
spectrometers 1282, 1284, 1286, 1288, 1290, 1344, 1346, and 1348 by
data cables 1292, 1294, 1296, 1298,1300,1350, 1352, and 1354
respectively. The processor 1360 further analyzes the combined
light energy received by the spectrometers. The processor 1360 then
compares these results to a pre-determined or pre-assigned value
that represents an acceptable measurement of the package (i.e. a
package with an acceptable level of defects). The comparison value
can either be obtained by a calibration run as described above or
can be input into the processor based on known values. If the
defect level does not conform to the comparison value, a rejection
unit 1365 coupled to the processor 1360 sends a signal to the
packaging line to discard or remove the package containing the
defect.
[0062] FIG. 8 shows a general schematic representation of a light
energy aggregator 1500 utilized in an inspection system constructed
in accordance with the present invention. The light energy
aggregator 1500 collects the light signals transmitted by a number
of fiber optic input cables, aggregates the light signals, and
transmits the aggregated light signals as a single light energy
output. Preferably, the light energy output represents an average
reflectance value obtained through the several fiber optic input
cables. The light energy aggregator 1500 includes a housing 1535
having an input end 1536 and an output end 1538. The input end 1536
includes input terminals 1520, 1522, 1524, 1526, and 1528 which
connect fiber optic input cables 1502, 1504, 1506, 1508, and 1510
respectively to the light energy aggregator housing 1535. A fewer
or greater number of input terminals also are contemplated. The
input terminals are preferably an SMA or other type of known fiber
optic connection device. The output end 1538 includes a single
output terminal 1532 connected to an output fiber optic cable 1530.
Alternatively, the individual light input optical fibers 1502-1510
may be combined into the single output bundle 1530 without the use
of any intervening fiber optic connectors.
[0063] FIGS. 9-12 show a preferred embodiment of a light energy
aggregator utilized in accordance with the present invention. The
light energy aggregator embodied in FIGS. 9-12 utilizes a splitter
block 1540. In conjunction with an inspection system constructed in
accordance with the present invention, sample probes 1550 and 1555
take light energy readings from an item to be sampled and bring the
collected light energy to the splitter block 1540. Each of the two
sample probes 1550 and 1555 in FIG. 9 contain two fiber optic
strands 1553 and 1554 (See cross section in FIG. 10). The fiber
optic strands 1553 and 1554 are encased in an insulating and
non-light transmitting material 1552. The entire probe 1550 is
contained in a PVC sheathing 1551. Connection devices 1560 and 1565
connect each of the sample probes to a flexible tube 1570 or 1575
which can be directed to an input end 1542 of the splitter block
1540. While the light energy aggregator shown in FIGS. 9-12
utilizes two sample probes, it is contemplated that any number of
sample probes and corresponding fiber optic strands can be utilized
in an inspection system constructed in accordance with the present
invention.
[0064] Again referring to FIG. 9, the splitter block 1540 includes
a single bundled cable 1580 coupled to an output end 1544 of the
splitter block 1540. The cable 1580 leads to a spectrometer
connector 1590 having a spectrometer input tip 1595. In conjunction
with the splitter block 1540, the input tip 1595 functions to bring
all of the collected light energy from each of the sample probes
(in this case 1550 and 1555) to a spectrometer. The input tip 1595
is therefore adapted to engage with a light entrance slit of a
spectrometer.
[0065] FIG. 11 shows a cross-section of the splitter block 1540.
While the cross-section of FIG. 11 is representative of the
splitter block shown in FIG. 9, nine probe connections are shown
rather than the two embodied in FIG. 9. The nine probe connections
1600, 1602, 1604, 1606, 1608, 1610, 1612, 1614, and 1616 are
substantially identical in structure, each including two separate
fiber optic strands. The splitter block 1540 combines the eighteen
(18) total fiber optic strands engaging the input end 1542 of the
splitter block into a single bundled cable 1580 engaging the output
end 1544. The bundled cable 1580 is preferably covered with a PVC
sheathing 1585. FIG. 12 shows a cross section of the input tip 1595
of the bundled cable 1580 as it is adapted to align and couple with
the entrance slit of a spectrometer.
[0066] The splitter block embodiment of a light energy aggregator
depicted in FIGS. 912 is one example of such a light energy
aggregator and other embodiments of a device that combines the
light energy from two or more sample probes are contemplated by the
present invention. For example, another embodiment of a light
energy aggregator uses a reflective chamber to receive collected
light energy from each of the sample probes. As all of the light
energy is combined within the light chamber, a single output
distributes the aggregated light energy and directs it through a
single fiber optic strand. This single fiber optic strand is then
directed to the entrance slit of a spectrometer. Such an embodiment
of a light energy aggregator is beneficial since it reduces the
complexity of the entrance slit connection. The reflective chamber
is preferably highly polished, such as a gold plated finish or
electro-polished stainless steel, so that light energy losses are
kept to a minimum.
[0067] FIGS. 13-15 show a preferred embodiment of an inspection
head 1700 as it mounts over a conveyer-based packaging line and
inspection system. The inspection head 1700 includes a probe
housing 1715 mounted over a conveyer unit 1710. The conveyer unit
1710 includes a pair of channels 1712 and 1714 that are adapted to
carry, for example, filled blister packages past the inspection
head 1700 and its associated sample probes. The inspection head
1700 also includes near-infrared light source housings 1725a and
1725b mounted on either side of the conveyer unit 1710. The two
housings 1725a and 1725b contain a near-infrared light source that
is directed at the channels 1712 and 1714 where the items to be
inspected travel. It is contemplated that in other embodiments, the
number of channels in the conveyer unit 1710 may be more or less
than two.
[0068] In FIG. 14, a front faceplate of the probe housing is
removed to illustrate the arrangement of an array of sample probes
1730. Generally, the sample probes 1730 are positioned so that they
each align with a single item in a package 1716 passing beneath.
FIG. 14 is shown with four individual sample probes corresponding
to each of the packages 1716, since each of the packages contain
four items in FIG. 14. Of course, in a system adapted to inspect
packages with a different number of items, a corresponding number
of sample probes would be included. Preferably, the probe housing
1715 can be easily retooled to accommodate a varying number of
sample probes, for example, probe housing modules having a set
number of sample probes can be utilized to easily change the format
of the inspection head. Also, a probe mounting plate that has a
pattern of holes for holding the probes positioned above each of
the items may be utilized. The probe mounting plate may be adapted
to be easily changed to accommodate a different layout of items.
Pre-assembled sample probe manifolds can also be utilized to
accomplish the goal of an easy exchange for use with different
packaging and inspection systems that utilize varying sized
packages. An array of fiber optic cables 1740 connects each of the
sample probes to a spectrometer housing 1720 mounted above the
sample probe housing 1715.
[0069] FIG. 15 shows a cross section of the inspection head 1700
and more particularly the connections between the sample probes
1730, the fiber optic cables 1740, a light energy aggregator 1750
and a spectrometer 1760. Preferably, the light energy aggregator
1750 and the spectrometer 1760 are both mounted within the
spectrometer housing 1720 although it is contemplated that the
light energy aggregator may be positioned elsewhere in the
inspection head 1700. It is also contemplated that the light
aggregator 1750 and/or the spectrometer 1760 may be located outside
of the inspection head 1700. FIG. 15 illustrates how the sample
probes 1730 align with each of the items contained in the package
1716 and combine the signal gathered by the probes in the light
energy aggregator 1750. The combined signal is then transferred to
the spectrometer 1760 for processing.
[0070] FIGS. 16 and 17 present several flow charts describing
methods of inspection and analyzing reflectance data in accordance
with the present invention. In FIG. 16, a method 1800 includes
illuminating a target or package at 1810 and then obtaining a
reference reflectance value for that package at a 1820. The
reference reflectance value can be obtained either by a calibration
run 1825 or by inputting the known values at 1830.
[0071] After the reference reflectance value is obtained, reflected
light is collected at 1835 from all items in the target package.
This reflected light is combined at 1840 and input into a
spectrometer at 1845 where the light energy is measured and the
reflectance calculated at 1850. A comparison is made between the
reference reflectance value and the acquired reflectance value at
1855 and a determination is made at 1860 whether the acquired
reflectance data falls within the reference data acceptance
criteria. If the acquired reflectance data is acceptable the
process continues at 1865, a next target or other sample is
prepared at 1875 and the process repeats at 1890. If the acquired
reflectance data is not within acceptable criteria, the target
package is rejected at 1870, a next target or other sample is
prepared at 1875, and the process repeats at 1890.
[0072] Turning to FIG. 17, a method 1900 includes illuminating a
target or package at a 1905 and then obtaining a reference
reflectance value for that package at 1910. The reference
reflectance value can be obtained either by a calibration run 1915
or by inputting the known values at 1920. At 1925, item-by-item
reflected light is collected, and then a determination is made at
1930 whether more detailed information about the package
reflectance data is required, i.e. whether column-by-column or
row-by-row reflectance data is desired. If the more detailed
reflectance data is required, then the column data is sorted at
1935, the row data is sorted at 1940 and the row and column data
are combined at 1945. The combined reflected light is then input
into a spectrometer at 1955. If row and column specific information
is not required then reflected light is combined for all of the
items in the package at 1950, and the combined reflected light is
input into a spectrometer at 1955.
[0073] The light energy is measured and reflectance calculated at
1960, a comparison is made between the reference reflectance value
and the acquired reflectance value at 1965, and a determination is
made at 1970 whether the acquired reflectance data falls within the
reference data acceptance criteria. If the acquired reflectance
data is acceptable the process continues at 1975, a next target is
prepared for inspection, and the process repeats.
[0074] If the acquired reflectance data is not acceptable a further
determination is initiated at 1980 to isolate the location of the
non-conforming item or items within the package. Once the
non-conforming item or items are located, the target package is
rejected at 1985 and the location data is sent to a user for
further processing or analysis at 1990. Alternately, the rejected
package is automatically sorted and the conforming items are
reinserted into the packaging system. The inspection process
continues by preparing a next target for inspection and repeating
the inspection process.
[0075] As mentioned above, an inspection device constructed in
accordance with the present invention is preferably used in
conjunction with a pharmaceutical packaging system, although it is
contemplated that such an inspection system can be used with a
variety of other applications such as food manufacturing/packaging,
consumer goods, as well as industrial applications.
[0076] The methods and systems outlined above for inspecting and
analyzing packaged items utilize an individual sample probe to
collect the reflected light from each item in the package. The
sample probes in the above examples and embodiments are aligned
with the individual items in the package. This technique is most
applicable when the location within the package of the item being
analyzed is well known, such as when a standardized packaging unit
is used, i.e. a blister pack for a regularly processed
pharmaceutical. Other examples include oral contraceptive
packaging, antihistamine packaging, and vitamin packages where
multiple dosage formats are included in a single package, e.g. day
and night antihistamine dosages or contraceptive dosages.
[0077] For situations where the location within the package of each
item is not predetermined, the concepts of imaging spectrometry may
be utilized in accordance with an embodiment of the present
invention to identify the individual item locations. In addition to
identifying the item location within a package, an imaging
spectrometer can be simultaneously used in accordance with an
embodiment of the present invention to capture the spectrum of the
individual items for analysis.
[0078] Imaging spectrometers simultaneously capture data in as many
as hundreds of contiguous registered spectral bands, such that a
spectral vector containing as much information as an individual
spectrometer spectrum is measured for each picture element (pixel).
The field of view of an imaging spectrometer may be considered as a
collection of picture elements (pixels) or resolution elements
(reselms). This field can be imaged onto an array of detector
elements in a focal plane array (FPA), or it may be imaged by a
single detector or small array that is scanned over the field.
Further information and details regarding imaging spectrometers can
be found in Introduction to Imaging Spectrometers, William L.
Wolfe, 1997, which is hereby incorporated by reference.
[0079] Generally, in a push-broom scanning-type imaging
spectrometer, the spectral data is acquired one image line at a
time. By moving the items to be scanned underneath the imaging
element a second spatial dimension is provided, a two dimensional
spatial image can be developed with a third spectral dimension.
With a complete image field of a package obtained, identification
and isolation of individual items within the package of items can
be made by comparing the spectra obtained at each pixel with the
corresponding pixel from a known background, i.e. an unfilled
package. After the pixels corresponding to the filled package and
the product items within the package have been isolated, any one of
the analyses described above in conjunction with FIGS. 1-17 can be
applied to determine whether the package items conform to a
predetermined standard.
[0080] A push broom imaging spectrometer (IS) is one that uses a
2-D detector array. One dimension of the detector is used to
collect the spatial information (i.e. it images a row of spatial
pixels corresponding to the various positions across the conveyor
transporting the items by the head) and the other is used to
collect the spectral information (i.e. each column of the array
simultaneously measures the spectrum corresponding to a single
spatial pixel). The image is acquired one line at a time. Optics
are used to project an image of the surface under observation onto
the entrance slit of the IS. The height of the entrance slit
defines the height of the spatial pixels in the final image. Inside
the IS, the dispersed image of the light transmitted through the
entrance slit is focused onto the 2-D detector array. The wide
dimension of the entrance slit is focused across the width of the
detector array. Thus, the width of the detector in pixels is equal
to the width of the spatial image in pixels.
[0081] The grating disperses the light perpendicular to the wide
dimension of the entrance slit. Thus, the other dimension of the
detector is used to collect the spectral information. The number of
wavelengths measured corresponds to the dimension of the detector
in this direction.
[0082] The second spatial dimension is acquired by moving the
sensor relative to the surface under observation. The end result is
a 3-D data set: 2 spatial and one spectral dimension.
[0083] Standard image analysis routines are used to define the
centers of the items under inspection. Spectra corresponding to
these center pixels (one or more pixels averaged for each item
depending on the size of the item and the size of the spatial
pixels) are then analyzed in the same manner as the non-IS example.
Also note that because a complete image is acquired, the IS-based
approach also provides the shape of the items under inspection.
[0084] With reference to FIG. 18, a push-broom scanning imaging
spectrometer system 2000 constructed in accordance with an
embodiment of the present invention is shown. The imaging
spectrometer system 2000 is preferably used to obtain item-location
data corresponding to a package 2030 that contains, for example, an
array of items 2040. As an example, the package 2030 may comprise a
blister pack that includes an array of tablet wells shaped and
sized to each hold an individual tablet. The spectrometer system
2000, includes an imaging spectrometer 2010 and a fore-optics unit
2015. The push broom scanning spectrometer 2000 is mounted above a
conveyer system 2020 that carries the package 2030 through a field
of view 2017 of the fore-optics unit 2015. The conveyer system 2020
is similar to those described in conjunction with FIGS. 1-15.
[0085] Also shown on the conveyer 2030 is an unfilled, or "blank"
package 2025. The blank package 2025 in FIG. 18 also shows empty
tablet wells 2035. The direction of the conveyer movement is
indicated by an arrow 2027 and illustrates how the blank package
2025 passes the imaging element 2015 first, thereby providing a
reference image. When the filled package 2030 passes the imaging
element 2015, the spectral data gathered can be compared to the
reference image previously obtained and a determination can be made
as to the specific locations of the individual items 2040 within
the package 2030.
[0086] Preferably, there are two reference images. The first
without items in place, the second with items in place. These
reference images can then be used to indicate the general location
of each item with the specific location determined by standard
image processing methods applied to the new image of each group of
items. Alternatively, the system can use the reference image (this
time only with the tablets in place) to train the system to
recognize the items wherever they are located within the system's
field-of-view.
[0087] FIGS. 19A-19C show a plan view representing the product
packages that correspond to the embodiment of FIG. 18. FIG. 19A
shows a blank package 2100 having a four-by-four array of item
locations 2110. Each item location includes a tablet well 2115.
FIG. 19B shows a filled package 2125. The arrangement of the
package 2125 is identical to that of the package 2100 except that
tablets 2130 are loaded into each of the tablet wells 2115.
Finally, FIG. 19C illustrates how the imaging spectrometer scans
the package 2125 one image line at a time. A single row of image
pixels 2160 is scanned in a given time frame by the spectrometer.
As the package 2125 passes beneath the scanning element, sequential
rows of image pixels are scanned until an array of pixels 2155 is
formed. The array 2155 represents an image of the package 2125. The
package image is then compared to the reference image previously
obtained and the item locations can be precisely ascertained.
[0088] FIG. 20 depicts a scanning method 2200 in accordance with an
embodiment of the present invention. The spectral reference images
of both a blank, unloaded package, and a filled package are first
obtained at 2210. The spectral image of a package under inspection
is obtained at 2215. Obtaining the spectral image of a package
under inspection 2215 is shown in more detail in FIG. 20 as
collecting the first line of the image at 2220, incrementing the
position of the package at 2222, and looping back to 2220 until the
complete image is acquired at 2224. The reference spectral image(s)
are compared with the spectral image of the package under
inspection at 2230, the item locations are then determined, and the
image pixels corresponding to the item locations are isolated at
2240. Spectral analysis of the item compositions can then be
accomplished by any of the methods and systems previously described
and illustrated as well as by other known inspection systems and
methods.
[0089] Although the present invention has been described and
illustrated in the above description and drawings, it is understood
that this description is by example only and that numerous changes
and modifications can be made by those skilled in the art without
departing from the true spirit and scope of the invention. The
invention, therefore, is not to be restricted, except by the
following claims and their equivalents.
* * * * *